linux_dsm_epyc7002/arch/x86_64
Linus Torvalds dbe3ed1c07 x86-64: page faults from user mode are always user faults
Randy Dunlap noticed an interesting "crashme" behaviour on his dual
Prescott Xeon setup, where he gets page faults with the error code
having a zero "user" bit, but the register state points back to user
mode.

This may be a CPU microcode buglet triggered by some strange instruction
pattern that crashme generates, and loading a microcode update seems to
possibly have fixed it.

Regardless, we really should trust the register state more than the
error code, since it's really the register state that determines whether
we can actually send a signal, or whether we're in kernel mode and need
to oops/kill the process in the case of a page fault.

Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-19 11:37:14 -07:00
..
boot x86_64: Early segment setup for VT 2007-08-11 15:58:13 -07:00
crypto [CRYPTO] api: Get rid of flags argument to setkey 2006-09-21 11:41:02 +10:00
ia32 Remove fs.h from mm.h 2007-07-29 17:09:29 -07:00
kernel Pull bugzilla-1641 into release branch 2007-08-24 22:19:05 -04:00
lib Do not replace whole memcpy in apply alternatives 2007-08-12 01:42:37 -07:00
mm x86-64: page faults from user mode are always user faults 2007-09-19 11:37:14 -07:00
oprofile [PATCH] Move Kprobes and Oprofile to "Instrumentation Support" menu 2005-11-07 07:53:35 -08:00
pci x86: Work around mmio config space quirk on AMD Fam10h 2007-08-11 15:58:12 -07:00
vdso x86_64: Add missing mask operation to vdso 2007-09-12 09:28:06 -07:00
defconfig PM: Fix dependencies of CONFIG_SUSPEND and CONFIG_HIBERNATION 2007-08-31 01:42:22 -07:00
Kconfig [IA64] Fix build failure in fs/quota.c 2007-07-27 15:40:13 -07:00
Kconfig.debug Allow DEBUG_RODATA and KPROBES to co-exist 2007-06-21 16:02:50 -07:00
Makefile x86_64: Check for .cfi_rel_offset in CFI probe 2007-08-18 10:25:25 -07:00